LASER GLASS HOST COMPOSITIONS COMPRISING TeO{11 , SrO AND ZnO

ABSTRACT

Laser glass host compositions for effective lasing amounts of Nd2O3 are disclosed, the host compositions comprising TeO2, SrO and ZnO in certain molar amounts. Also disclosed are methods of making highly effective laser articles, such as rods, and the new use of the above described glass compositions for forming laser articles, the new use including forming lasert articles from the compositions, pumping the resultant laser articles to provide an energy inversion, and lasing the pumped article.

United States Patent 11 1 Cooley 1 Oct. 29, 1974 LASER GLASS HOST COMPOSITIONS COMPRISING TEO2, SRO AND ZNO [75] Inventor: Richard F. Cooley, Toledo, Ohio [73] Assignee: Owens-Illinois, lnc., Toledo, Ohio [22] Filed: June 27, 1973 [2]] Appl. No.: 373,925

52 us. c1 331 945 E, 252/3014 R, 252/3016 R, 10 /47 Q 51 Int. Cl H01s 3/00, C036 3/12, c03 3/30 58 Field of Search 106/47 0,47 R; 331/945 E; 252/3014 R, 301.4 F, 301.6 R

[56] References Cited UNITED STATES PATENTS 3,423,326 l/l969 Redman....................... 2S2/30l.6 R

FOREIGN PATENTS OR APPLICATIONS 736,073 8/l955 Great Britain l06/47 Q 741,986 12/1955 Great Britain l,496,56l 9/1972 Germany l06/47 Q OTHER PUBLICATIONS Stanworth, Tellurite Glasses," J. Soc. Glass Tech., vol. 36, (I952) pp. 217-241, TP 845 S 678.

Primary Examiner-Winston A. Douglas Assistant Examiner-Mark Bell Attorney, Agent, or Firm-Richard D. Heberling; E. J. Holler 5 7 ABSTRACT 8 Claims, 1 Drawing Figure LASER GLASS HOST COMPOSITIONS COMPRISING TEO SRO AND ZNO INVENTION The present invention relates to laser glass host compositions for effective lasing amounts of Nd O the host compositions comprising TeO SrO and ZnO in certain molar amounts. The present invention also relates to methods of making laser articles, such as rods, with increased efficiency, the methods including the steps of:

l. forming laser articles from glass compositions comprising certain amounts of TeO SrO and ZnO, the glass composition being a host for an effective lasing amount of Nd o 2. pumping the laser article to provide an energy inversion; and

3. lasing the pumped article.

The present invention also relates to a method for making an outstanding, highly efficient glass laser article. such as a rod, or a disc by:

l. melting laser glass batch-fonning materials to provide a molten glass comprising certain amounts of Teo SrO. ZnO and an effective lasing amount of 2. forming a glass blank from the molten glass; and

3. fabricating the outstanding laser articles from the blank.

It is highly desirable to provide laser glass compositions that can be used to make outstanding highlyefficient glass laser articles. lt is also desirable to provide a new use for glass compositions comprising TeO SrO and ZnO in which the new use includes the steps of:

l. forming a glass laser article from the abovedescribed glass composition that is a host for an effective lasing amount of Nd O 2. pumping the laser article; and thereafter 3. lasing the pumped article.

It is an object of the present invention to provide a laser glass composition containing TeO SrO and ZnO in which the proportions of TeO SrO and ZnO, in molar amounts, are defined by the area within the heavy lines connecting the points ABCDEF of the ternary diagram of the FlGURE, and the glass composition is a host for an effective lasing amount of Nd,O

lt is an object of the present invention to provide a method for making a glass article such as a laser rod, disc or the like, in which the method comprises the steps of:

l. melting laser glass batch-forming materials to provide a molten glass comprising TeO SrO and ZnO, in which the proportions thereof, in molar amounts, are defined by the area within the heavy lines connecting points ABCDEF of the ternary diagram of the FIGURE the molten glass being a host for an effective lasing amount of Nd O 2. forming a glass laser blank from the molten glass; and

3. fabricating a laser article from the blank to provide a very efficient laser article.

It is an object of the present invention to provide a new use for a glass composition as a glass laser article in which the glass comprises TeO SrO and ZnO in certain proportions thereof and in which the glass composition is a host for an effective lasing amount of Ndgoa, the new use comprising the steps of:

l. forming a glass laser article from the glass composition comprising 11:0,, SrO and ZnO, along with the effective lasing amount of Nd,0

2. pumping the laser article to provide an energy inversion; and

3. lasing the pumped laser article.

It is an object of the present invention to provide a highly-efficient glass laser article, such as a rod or disc, made from a glass composition comprising TeO SrO and ZnO, and containing an effective lasing amount of Nd,0,.

These and other objects will become apparent from the specification that follows, the appended claims, and the drawings, in which the FIGURE is a ternary diagram of the glass host composition of the present invention in which the molar proportions of TeO SrO and ZnO are defined by the area within the heavy lines of the ternary diagram.

The present invention provides outstanding laser glass host compositions for effective lasing amounts of M 0 the host compositions comprising TeO SrO and ZnO in certain molar amounts that are defined generally by the area within the heavy lines connecting the points ABCDEF of the ternary diagram of the FIG- URE of the drawings. Preferably, the molar amounts of TeO SrO and ZnO are defined by the area within the heavy lines connecting the points GHLIKL in the ternary diagram.

The present invention also provides methods for making highly efficient glass laser articles, such as rods or discs, the methods including the steps of:

l. melting laser glass batch-forming materials to provide a molten glass comprising TeO SrO and ZnO in which the molar amounts thereof are defined generally by the area within the heavy lines connecting the points ABCDEF of the ternary diagram, the molten glass capable of acting as a host for an effective lasing amount of Nd O 2. forming a glass blank from the molten glass; and

3. fabricating the outstanding laser articles from the blank.

The present invention also provides the new use for a glass composition as a glass laser article in which the glass comprises TeO SrO and ZnO, in which the proportions thereof, in molar amounts, are defined generally within the area formed by the heavy lines connecting points ABCDEF of the ternary diagram, in which the glass composition is a host for an effective lasing amount of Nd,0;,, the new use comprising the steps of:

l. forming a glass laser article from the glass composition comprising Te0,, SrO and ZnO, with an effective lasing amount of Nd,O

2. pumping the laser article to provide an energy inversion; and

3. lasing the pumped laser article.

A zinc tellurite glass consisting essentially of a major molar proportion of TeO and between about 20 and 40 molar percent of ZnO is described and claimed in Redman, U.S. Pat. No. 3,423,326. These zinc tellurite glasses were reported as having some fluorescent activity when doped with Nd O As previously indicated, the outstanding laser glass host compositions of the present invention surprisingly exhibit much higher fluorescent activity than the zinc tellurite glasses of U.S. Pat. No. 3,423,326, the increased fluorescent activity indicating a greater lasing efficiency for laser articles made from the host compositions of the present invention. As previously described, only certain molar proportions of TeO SrO and ZnO can be used to provide the highly efficient laser articles, such as rods and discs. The increase in fluorescent activity is generally at least about 50 percent and preferably at least about 60 or 70 percent. the increase often being as much as 100 percent or more. The increase is at least 50 percent when compared to the working examples of the Redman patent.

In the previously mentioned Redman US. Pat. No. 3,423,326, there is no mention of any glass system other than that of a glass host composition consisting essentially of tellurium oxide and zinc oxide. There is no suggestion in the previously mentioned Redman patent that highly efficient laser articles can be made from a host composition containing certain molar proportions of TeO SrO and ZnO.

The outstanding laser glass host compositions of the present invention generally contain about 55-90 mole percent TeO- about 2-15 mole percent SrO and about 5-38 mole percent ZnO. As previously indicated, this host glass contains an effective lasing amount of Ndgog which preferably is about 0.0l-l.5 mole percent.

Preferred compositions are those in which the glass host comprises about 63-65 mole percent Teo about 3-6 mole percent SrO, and about 30-33 mole percent ZnO, the host composition containing a preferred amount of Nd O which is in the range of about 0.0l-l .5 mole percent.

Excellent glass laser compositions are those, for example. in which the host glass comprises about 65 mole:

percent TeO about 5 mole percent SrO, and about 30 mole percent ZnO or a glass that comprises about 64 mole percent TeO about 6 mole percent SrO, and 30 mole percent ZnO, or a glass that comprises about 63 mole percent TeO about 4 mole percent SrO and about 33 mole percent ZnO.

In accordance with the present invention, increased lasing efficiency is obtained for glass laser rods and discs. The increase in fluorescent activity is surprisingly at least about 50 percent over that of a zinc tellurite glass containing 65 mole percent TeO, and 35 mole percent ZnO and at least 50 percent over that of a lithia-calcia-alumino silicate glass laser rod containing:

Ingredient Mole Percent SiO (i Ago, 2.5 Li,O 27.5 (110 ll) Nap.

EXAMPLE 1 PART A A l5 gram melt was prepared by mixing reagent grade raw materials, in the following molar percent and also for convenience, weight percent, with 30 ml. of water.

Mole percent Weight percent Rust. Laser Hus! Laser Ingredients Glass Article Glass Article T120, 85.0 84.5 9 l .l 89.0 ZnO [0.0 9.9 5.4 5.3 SrO 5.0 4.) 4.5 3.4 Nap, 0.x 1.7

The slurry was mixed for ID minutes and poured into a gold crucible. The crucible was placed in an air circulating oven with the temperature maintained at l l0C. overnight to remove the water. The crucible was then placed in an electric resistance furnace with the temperature at 750C. for 3 hours. or until homogenous, after which the molten glass immediately poured into a preheated (260C) graphite mold forming a disc having an ll/l6 inch diameter and V4 inch thickness. The

graphite mold was placed in an annealing oven main- PART B The polished glass disc from Part A was tested for fluorescence intensity and decay time in a high power pulsed test system. The disc was placed in a holder and exposed to a beam of light from an EC & G model FX l2-25 xenon flashlamp. The flashlamp has a flash duration of about 20 microseconds. The disc was not observed to solarize after repeated excitation by the flashlamp. The fluorescence intensity and decay time of the excited sample was measured by photographing the oscilloscope display of the 1,060 nanometer fluorescent intensity versus time on a Tektronix Model 556, Dual Trace oscilloscope connected to an RCA S-l photomultiplier having a narrow band pass filter.

The fluorescence intensity measurement was normalized against ED-2, a glass laser composition of Owenslllinois, lnc., comprising, in mole percent, 60.0% Si0 2.5% A1 0 27.5% Li O, l0% CaO, 0.16% CeO and 0.5% Nd O disclosed in U.S. Pat. No. 3,471,409 as Example l. The fluorescence intensity was found to be 3.15 when normalized against the glass laser composition; 3. l 5 times the intensity of the glass laser composition.

The fluorescence intensity was corrected for the refractive indices of the glass disc and the reference glass laser composition by Fl (corrected) Fl (normalized) l(l.56) /(n glass discl l The corrected fluorescence intensity was 1.63. The fluorescence decay time was 147 microseconds.

EXAMPLE 2 PART A A gram melt was prepared and polished glass discs prepared therefrom as described in Part A of Example 1 except the molar or weight percentages of the raw materials were as follows:

The refractive index of the finished polished glass disc was measured to be 2.08.

PART B The polished glass disc from Part A was tested for fluorescence intensity and decay time as described in Part B of Example I. The normalized fluorescence intensity was 3.1 and the corrected fluorescence intensity was 1.69. The fluorescence decay time was 154 microseconds.

EXAMPLE 3 PART A A 15 gram melt was prepared and polished glass discs prepared therefrom as described in Part A of Example 1 except the molar or weight percentages of the raw materials were as follows:

Mole Percent Wgight Percent Host Laser Host Laser Ingredients Glass Article Glass Article T00, 66.7 66.3 79.1 77.8 2110 28.3 28.1 17.1 l6.ti SrO 5.0 4.9 3.91 3.7 Nd,O, 0.7 1.8

The refractive index of the finished polished glass disc was measured to be 2.06.

PART B The polished glass disc from Part A was tested for fluorescence intensity and decay time as described in Part B of Example I. The normalized fluorescence intensity was 2.29 and the corrected fluorescence intensity was 1.27. The fluorescence decay time was 162 microseconds.

EXAMPLE 4 PART A A 15 gram melt was prepared and polished glass discs prepared therefrom as described in Part A of Example 1 except the molar or weight percentages of the raw materials were as follows:

Mole Pgrgggt Weight Pcrggnt Host Laser Host Laser Ingredients Glass Article Glass Article TeO; 63.7 63.0 76.8 75.4 ZnO 31.3 31.6 19.5 19.2 SrO 5.0 4. 7 3.7 3.6 Nd,0;, 0.7 1.8

The refractive index of the finished polished glass disc was measured to be 2.04.

PART B The polished glass disc from Part A was tested for fluorescence intensity and decay time as described in Part B of Example 1. The normalized fluorescence intensity was 2.73 and the corrected fluorescence intensity was 1.55. The fluorescence decay time was 154 microseconds.

Other specific compositions set forth as being suitable for use in the present invention can be substituted for the specific glass laser compositions used in the working examples to provide substantially equivalent results; for instance. any of the compositions set forth within the area formed by the heavy lines connecting the points ABCDEF of the ternary diagram can be used in place of the specific laser compositions used in the working examples. Thus, a host glass comprising about mole percent TeO about 5 mole percent SrO and about 30 mole percent ZnO can be used for the specific host composition set forth in Examples 1 and 2. Likewise, a laser glass host composition comprising 64 mole percent TeO about 6 mole percent SrO, and 30 mole percent ZnO, as well as a glass host comprising about 63 mole percent TeO about 4 mole percent SrO, and about 33 mole percent ZnO. can be used to provide substantially equivalent results.

What is claimed is:

l. A laser glass, host composition comprising TeO SrO and ZnO in which the proportions of TeO SrO and ZnO in molar amounts are defined by the area within the heavy lines connecting the points ABSDEF of the ternary diagram of the FIGURE of the drawings, the laser glass host composition being a host for an effective lasing amount of Nd O 2. A laser glass host composition as defined in claim 1 in which the proportions of T602, SrO and ZnO are defined by the areas within the heavy lines connecting the points GHIJKL in the ternary diagram of the FIG- URE of the drawings.

3. A laser glass composition comprising:

1. a host glass containing about 55-90 mole percent TeO about 2-15 mole percent SrO, and about 5-38 mole percent ZnO; and

2. an effective lasing amount of Nd O 4. A laser glass host composition comprising about 63-65 mole percent TeO about 36 mole percent Sr(), and about 3-33 mole percent ZnO. the host composition containing about 0.01-l .5 mole percent Nd 0 5. A laser glass composition as defined in claim 3 in which the host glass comprises about 64 mole percent TeO about 5 mole percent Sr(), and about 30 mole percent ZnO.

6. A laser glass composition as defined in claim 3 in which the host glass comprises about 64 mole percent 7 8 TeO about 6 mole percent SrO, and about 30 mole the FIGURE of the drawings, and which glass composipercent ZnO. tion is a host for an effective lasing amount of Nd- O 7. A laser glass composition as defined in claim 3 in the new use comprising the Steps of: which the glass host comprises about 63 mole percent gsg i g mole percent and about 33 mole 5 sition comprising TeO SrO and ZnO with an ef- 8. The new use for a glass composition as a glass laser 133mg ajmoum P N120"; i article in which the glass comprises TeO SrO and ZnO pumpmg the laser amcle to Provlde an energy in which the proportions thereof in molar amounts are verloni and defined within the area formed by the heavy lines conla lng he pumped laser article. necting the points ABCDEF of the ternary diagram of 1. forming a glass laser article from the glass compo- 

1. A LASER GLASS, HOST COMPOSITION COMPRISING TEO3, SRO AND ZNO IN WHICH THE PROPORTIONS OF TEO2, SRO AND ZNO IN MOLAR AMOUNTS ARE DEFINED BY THE AREA WIHTIN THE HEAVY LINES CONNECTING THE POINTS ABSDEF OF THE TERNARY DIAGRAM OF THE FIGURE OF THE DRAWINGS, THE LASER GLASS HOST COMPOSITION BEING A HOST FOR AN EFFECTIVE LASING AMOUNT OF ND2O3.
 2. A laser glass host composition as defined in claim 1 in which the proportions of TeO2, SrO and ZnO are defined by the areas within the heavy lines connecting the points GHIJKL in the ternary diagram of the FIGURE of the drawings.
 2. pumping the laser article to provide an energy inversion; and
 2. an effective lasing amount of Nd2O3.
 3. lasing the pumped laser article.
 3. A laser glass composition comprising:
 4. A laser glAss host composition comprising about 63-65 mole percent TeO2, about 3-6 mole percent SrO, and about 3-33 mole percent ZnO, the host composition containing about 0.01-1.5 mole percent Nd2O3.
 5. A laser glass composition as defined in claim 3 in which the host glass comprises about 64 mole percent TeO2, about 5 mole percent SrO, and about 30 mole percent ZnO.
 6. A laser glass composition as defined in claim 3 in which the host glass comprises about 64 mole percent TeO2, about 6 mole percent SrO, and about 30 mole percent ZnO.
 7. A laser glass composition as defined in claim 3 in which the glass host comprises about 63 mole percent TeO2, about 4 mole percent SrO, and about 33 mole percent ZnO.
 8. The new use for a glass composition as a glass laser article in which the glass comprises TeO2, SrO and ZnO in which the proportions thereof in molar amounts are defined within the area formed by the heavy lines connecting the points ABCDEF of the ternary diagram of the FIGURE of the drawings, and which glass composition is a host for an effective lasing amount of Nd2O3, the new use comprising the steps of: 